RS-422 interface

Unanswered Question
May 6th, 2008
User Badges:

Hi There;

Has anyone connected an RS-422 interface with a Mil-STD-188/114 interface. Wikipedia ( - 6th paragraph) and the Mil Std website ( says that these two interfaces can interoperate despite there being a different voltage range! Does anyone know or have an opinion as to whether these two interfaces can interconnect? I'm concerned about short circuiting one or the other interface due to the different voltage range?


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3 (1 ratings)
amritpatek Mon, 05/12/2008 - 08:58
User Badges:
  • Silver, 250 points or more

The document says that EIA-422 can interoperate with interfaces designed to MIL-STD-188-114B, but they are not identical. EIA-422 uses a nominal 0 to 5 Volt signal while MIL-STD-188-114B uses a signal symmetric about 0 V. However the tolerance for common mode voltage in both specifications allows them to interoperate. Care must be taken with the termination network. Mean care must be taken during the connecting those interface

austindaz Mon, 05/12/2008 - 14:38
User Badges:

Hi There;

What would you say would happen when I connect both these interfaces together? Would you say it would work?



This Discussion